Getting Error while invoking Firefox browser .

Parent class:
public void openBrowser(String bType){
		if(bType.equals("Mozilla"))
		{
			driver = new FirefoxDriver();
		}
		else if(bType.equals("Chrome"))
		{
			System.setProperty("WebDriver.Chrome.driver", "C:\\Users\\manju\\Documents\\drivers.chromedriver.exe");
			driver = new ChromeDriver();
		}
		else if(bType.equals("IE")){
			System.setProperty("WebDriver.IE.driver", "C:\\Users\\manju\\Documents\\drivers\\IEDriverServer.exe");
			driver = new InternetExplorerDriver();
		}

I am calling openBrowser("Mozilla");
from child class.
But getting below excpetion

[RemoteTestNG] detected TestNG version 6.9.6
[TestNG] Running:
  C:\Users\manju\AppData\Local\Temp\testng-eclipse-2127447975\testng-customsuite.xml

FAILED: testB
java.lang.NoSuchMethodError: com.google.common.base.Preconditions.checkState(ZLjava/lang/String;Ljava/lang/Object;)V
	at org.openqa.selenium.remote.service.DriverService.checkExecutable(DriverService.java:146)
	at org.openqa.selenium.firefox.GeckoDriverService.access$000(GeckoDriverService.java:44)
	at org.openqa.selenium.firefox.GeckoDriverService$Builder.usingFirefoxBinary(GeckoDriverService.java:160)
	at org.openqa.selenium.firefox.FirefoxDriver.toExecutor(FirefoxDriver.java:187)
	at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:147)
	at org.openqa.selenium.firefox.FirefoxDriver.<init>(FirefoxDriver.java:125)
	at com.qtpselenium.core.ddf.base.Man.BaseTest.openBrowser(BaseTest.java:14)
	at com.qtpselenium.core.ddf.testcases.Man.DummyTestB_Man.testB(DummyTestB_Man.java:13)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
	at org.testng.internal.Invoker.invokeMethod(Invoker.java:639)
	at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:821)
	at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1131)
	at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:124)
	at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
	at org.testng.TestRunner.privateRun(TestRunner.java:773)
	at org.testng.TestRunner.run(TestRunner.java:623)
	at org.testng.SuiteRunner.runTest(SuiteRunner.java:357)
	at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:352)
	at org.testng.SuiteRunner.privateRun(SuiteRunner.java:310)
	at org.testng.SuiteRunner.run(SuiteRunner.java:259)
	at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
	at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
	at org.testng.TestNG.runSuitesSequentially(TestNG.java:1185)
	at org.testng.TestNG.runSuitesLocally(TestNG.java:1110)
	at org.testng.TestNG.run(TestNG.java:1018)
	at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:114)
	at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
	at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)


===============================================
    Default test
    Tests run: 1, Failures: 1, Skips: 0
===============================================


===============================================
Default suite
Total tests run: 1, Failures: 1, Skips: 0
===============================================

[TestNG] Time taken by [FailedReporter passed=0 failed=0 skipped=0]: 11 ms
[TestNG] Time taken by org.testng.reporters.SuiteHTMLReporter@7e0ea639: 77 ms
[TestNG] Time taken by org.testng.reporters.XMLReporter@7f690630: 14 ms
[TestNG] Time taken by org.testng.reporters.JUnitReportReporter@3498ed: 15 ms
[TestNG] Time taken by org.testng.reporters.EmailableReporter2@6cd8737: 18 ms
[TestNG] Time taken by org.testng.reporters.jq.Main@71be98f5: 186 ms